Screw driver



T. J. RICH EY Oct. 18, 1932.

SCREW DRIVER 2 Sheets-Sheet l Filed March 29. 19.30

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T. J. RICHEY SCREW DRIVER Oct. 18, 1932.

Filed March 29, 1930 2 Sheets-Sheet 2' e/zeg, 3mm

Patented Oct. 18, 1932 UNTED STATES PATENT OFFICE SAID THOMAS J'. BICHEY, DECEASED v scnnw DRIVER Application led March 29, 1930. Serial No. 440,046.

This invention relates to screw drivers and more especially to a toolof this type adapted to be driven by power.

Heretofore power-driven screw drivers have been objectionable because, when the head of the driven screw has reached a predetermined position, the end of the lscrew driver has frequently scarred the adjacent surface Vof the work before it has been possible to remove it from engagement with the screw.

It is an object of the present invention to provide a power-driven screw driver which will be automatically uncoupled from its driving mechanism as soon as the head of thek screw has been properly seated. Y

Another object is to provide a controlling mechanism which can be adjusted to advance or to delay the uncoupling operation, according to the ultimate position to which the head of the screw is to be brought relative to the surface of the work.

A still further object is to provide a tool Vof this character which is simple and compact and can be handled readily. Y

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combiunation and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

In the accompanying drawings the pre- :EerredV form of the invention has been shown.

In said drawings Figure 1 is an elevation of the tool.

Figure 2 is a longitudinal section through the casing of the toolshowing the interior mechanism in elevation and in its normal poportion of the tool besition, the lower end ing broken away. A f v Figure 3 1s a view similarl to Figure 2, the

interior mechanism being viewed at right' angles to Figure 2. Y

Figure 4 is a section on line 4 4, Figure 3. Figure 5 is aV section through a portion of the e001 taken on line 5 5, Figure 2, the' pawl heads being shown in elevation.

Figure 6 is a similar view showing the mechanism uncoupled.

Figure 7 is a section on line 7 7, Figure 4.

Figure Sis a section on line 8 8, Figure 5. v n

Figure 9 is a section on line 9 9, Figure 3.

Figure 10, is an elevation of the core.

Figure 11 is an elevation of one of the couplmg arms and its head, a portion being broken away.

Referring to the figures 'by characters vof reference, 1 designates a cylindrical housing having a stem 2 projecting from one end adapted to be connected in any suitable manner to a rotatable driving element. A bore 3 is extended into the housing from its other endl andat the inner end ofthis bore is provided a counterbore 4 surrounded by an interior annular shoulder 5. f

Seated in the bore 3 and bearingV against the shoulder 5 is a ring 6 having grooves 7 (see Figure 7) which receive lugs 8 extending in opposite directions from a nut 9. This nut engages a screw threaded stem 10fon which is mounted a lock nut 11 and this lock nut and one end of stem 10 is seated in the counterbore 4, being supported by nut 9 and ring 6. The ring isy held immovably in position by one or more screws 12 extend` Y the ring.

Recesses 14 are provided in Vone face of ring 6 and 'seated 1n each of these recesses 1s a coiled spring 15 which extends arounda latch pin 16. One end of this pin is anchored to spring 15, while the other end is extended well beyond the ring as shown.

Slidably mounted in the boreV 3 adjacenty to the ring 6 is a sleeve 17 connected by integral strips 18 to a ring 19 which is also slid-l able in bore 3 and is located close to the open end of the bore. Sleeve 17 has openings 2O in which the pins 16 are located and-each of the openings communicates with a recess 21 located in one edge of sleeve 17 and having jf a beveled inner or end wall. The springs 15 `THOMAS J'. RICHEY, OF LOUISVILLE, KENTUCKY; NELL SHADER ADMINISTRATRIX OF serve to hold pins 16 normally projected into the recesses 21. A stop pin 22 is carried by the sleeve 17 for engaging ring 6 to limit the relative axial movement of the ring and sleeve.

The ring 6 is formed integral with a tubular core 23 which is slidable in the sleeve 17 and between strips 18, this core being previded at one-end with an enlargement 24 connected by additional screws 12 to the housing 1. Short slots 25 are formed in the strips 18 and screws 26 which are carried by the enlargement 24 are adapted to slide within slots 25 so that core 23 and sleeve 17 will have a limited relative sliding movement.

Pivotally mounted vin the enlargement 24 are arms 27 the free ends of which are provided with beveled heads 28 adapted to work within the respective recesses 21 in sleeve 17 (see Figure 2). Springs 29 are Vinterposed between these arms and the core 23 and actl to press outwardly against the arms. Under normal conditions, however, the heads 28 are lapped by the projecting ends oi' the latch pins 16 so that the springs are held under restraint. Y

The shank 30 of the screw driver is rotatably mounted in the core 23 and has a longitudinal groove 31. The grooved portion oit' the shank extends into a sleeve 32 and a set screw 33 which is carried by this sleeve projects into groove 31 and holds the shank 30 and sleeve 32against relative rotation but allows limited relative sliding movement.

The sleeve 32 has an annular series ot'ribs or serrations 35 Vwhich are exposed through openings 36 provided in the core 23 and the heads 28 are toothed as shown at 37 so as to engage the adjacent ribs or Serrat-ions when the arms 27 are held under restraint by the latch pins 16. Vith the parts thus in engagement it is impossible for the core 23 to rotate independently of the shank 30. Y

The shank 30 has a pin or other projection 38 for receiving thrust from a light coiled spring 39 which bears at one end against the core 23. This spring is surrounded by a stronger coiled spring 40, one end of which bears against core 23 while the other end hears against one end of a. tripping sleeve 41. This sleeve is fitted detachably into the ring 19 to which it can be coupled by a pin 42 seated in a bayonet slot 43. The sleeve is extended around shank 30 and extends close to the bit 34.

It is to be understood that under usual conditions the screw 33 is used to prevent independent rotation oi shank 30 and sleeve 32 but permit limited longitudinal movement of the shank within the sleeve 32. In this eventspring 39 will act to hold the bit `34 normallyT projected its maximum distance.

Thus the bit can readily be placed in the kerf of a screw and when theV tool is pressed toward the work the end of the tripping.

Vseen that when the housing 1 is rotated by a power shaft or the like coupled to stem 2 the ring 6, which is fastened to the housing by screws 12 will also be rotated. This ring, in turn, will transmit motion through the core- 23 andscrews 26to the strips `18 and the parts integral therewith. Arms 27 will move with lthe parts 17,18,and 19 and cause the ribbed sleeve' 32 also to revolve. sleeve is coupled by screw 33 to shank 30,

said shank will be rotated with the housing 1.

Assuming that bit 34 is in engagement with a screw head and that the parts arerotating, it will be obvious that the screw will be driven into the work until the end of tripping sleeve 41 comes into contact with the surt'ace of the work." As soon as this action takes place the downward movementot ring 19 and the parts joinedI thereto will be stopped but a limited movement of housing 1 in a ydownward direction will take' place. This relative movement will cause the shoulder 5 and the screws 12 to move the core 23 downwardly so asto compress spring 40 and withdraw yheads 28 from engagement with the latch pins 16. Consequently arms. 27 will spring outwardly from engagement with the ribs 35 so that housing 1 and the parts coupled thereto can thus continue to rotate without rotating shank 30 and its bit 34.

Obviously by adjusting stem 1() the core 23 can be limited in its downward sliding movement on shank 30.

After the bit shank 30 has been uncoupled from the housing 1 as described, the parts can be reset by pulling the tripping sleeveV 41 outwardly from the housing. This wil-l cause the beveled ends oi' the heads 28 to be engaged by the walls ofthe recesses in sleeve 17 with the result that the heads will be pressed inwardly intoV engagement vwith the ribs 35. As soon as the reads are brought to these coupling` positions the latch pins will snap into lapping engagement with the heads whereupon the resetting of the tool` As this ing them against relative rotation, a latch carried by the sleeve for holding said means in engagement, and means movable relative to the bit shank and positioned adjacent to the active end thereof for engagement with the work to shift the sleeve and disengage said cooperating means to release the housing and core for rotation independently of the bit shank.

2. The combination with a driving housing and a core therein rotatably driven thereby, of a bit shank extending into the core and adjustable longitudinally thereof, means for limiting the longitudinal adjustment of the shank, a sleeve slidable on the core, co-operating means carried by the shank and core for holding them against relative rotation, a latch carried by the sleeve for holding said means in co-operative relation, yielding means for exerting a thrust against the core and sleeve to hold the latch normally in active position, and means for engagement with the work for holding the sleeve against longitudinal movement with the shank, thereby to disengage the latch from said co-operating means and release the housing for rotation independently of the shank.

3. The combination with a driving housing, a core therein rotatably driven thereby and a head movably connected to the core, of a bit shank, means carried by the shank for engagement by the head to hold the shank and core against relative rotation, a latch slidable in the housing for engaging the head to hold it against movement, means for automatically shifting the head when released from the latch, thereby to uncouple the shank from the core, and means :tor engagement with the work during the driving of a screw by the bit shank for shifting the latch to release the head.

4. The combination with a driving housing, a core therein rotatably driven thereby and a coupling head carried by the core, of a bit shank in the core, a sleeve coupled thereto, means on the sleeve for engagement by the head for coupling the shank to the housing, a latch engaging the head to hold it in coupled position, and means controlled by contact with a surface into which a screw is being driven for shifting the latch to release the head from coupling position.

5. The combination with a driving housing and a core rotatably driven thereby, of a head movably connected to the core, a bit shank, a sleeve carried by the shank, adjustable means for limiting the sliding movement of the shank in the sleeve, means on the sleeve for engagement by the head to couple the shank to the housing, a latch for holding the head in coupling position, and means for engagement with work during the driving of a screw annular series of projecting portions rotatable with the shank within the core, latches for engaging the heads for holding them under restraint and in engagement with the projecting portions to couplethe shank to the housing and core for rotation therewith, and means for engagement with work during the driving of a screw by the bit shank for shifting the latches relative to the core and release the heads, thereby to uncouple the housing and core 'from the shank.

' 7. The combination with a driving housing and a core rotatably driven thereby of a head movably connected to the core, a shank having a bit, an annular series of projecting portions rotatable with the shank, means for holding the head in engagement with said projecting portions to couple the shank to the housing for rotation together, and means for engagement with work during the driving ci a screw by the bit for shitting the latch to release the head from couplingposition.

8. The combination with a driving housing and a core rotatably driven thereby, of a head movably connected to the core, a shank having a bit, an annular series of projecting portions rotatable with the shank, means for holding the head in engagement with' said projecting portions to couple the shank to the housing for rotation together, and means for engagement with work duringthe'driving of a screw by the bit for shifting the latch to release the head from coupling position, said means including a sleeve slidable on the core and carrying the latch, a tripping sleeve movable with the latch sleeve, a spring interposed between and bearing against the core and tripping sleeve for holding the latch yieldingly in restraining position, and c0- operating means carried by the core and sleeves for limiting their relative sliding movement.

9. In a tool of the class described the combination with a driving housing, of a bit shank therein, means for -operatively connecting the bit shank and the housing for transmission o rotary motion from the housing to the shank, a tripping element extending from the housing adjacent to the shank, means controlled by the pressure of said element against the work for uncoupling the shank from the housing and means operated by the movement of the housing and tripping element in opposite directions respectively for actuating the coupling means to couple the housing to the shank.

In testimony that I claim the foregoing as my own, I have hereto aHiXed my signature.

THOMAS J. RICHEY.

by the bit shank for shifting the latch to rei lease the head.

6. The combination with a driving hous- 

